The present invention relates generally to a folding machine for folding one or more sheets of document into a folded piece and, more particularly, to a buckle chute.
Folding machines are well-known. For example, U.S. Pat. No. 4,701,233 (Beck et al.) discloses a method of folding a sheet by bulging a portion of the sheet and then folding the bulged portion through a roller nip. U.S. Pat. No. 4,875,965 (Marzullo) discloses a folding apparatus wherein a buckle chute is used for stopping a sheet, causing the sheet to enter a roller nip for folding. U.S. Pat. No. 4,944,131 (Gough) also discloses a folding apparatus having a buckle chute. In general, the sheet is allowed to enter into a channel of the buckle chute until the leading edge of the sheet is stopped by a stop. The leading edge stays in contact with the stop while the bulged portion is moved toward the roller nip for making a folded edge. The distance between the folded edge and the leading edge is usually adjustable. In the past, the buckle chute must first be removed from the folding machine and then the stop must be manually adjusted so as to change the distance between the folded edge and the leading edge. A series of markings indicating the folding distance are provided on the buckle chute to aid the positioning of the stop. While the folding distance can be roughly estimated by the markings, a precise folding distance is difficult to achieve. To obtain the correct folding distance, one may have to taking the buckle chute out of the folding machine a number of times to adjust the stop.
It is advantageous and desirable to provide a buckle chute wherein the folding distance can be precisely adjusted without the need of removing the buckle chute from the folding machine.
The present invention is concerned with a buckle chute having a front side, a back side, a left side and a right side for use in a sheet folding apparatus having a first driving mechanism and a second driving mechanism for folding at least one sheet of paper, having first and second lateral edges defining a width, into a folded piece of the same width, the first and the second lateral edges adjacent the left and right sides of the turn chute. The buckle chute is disposed between the first driving mechanism and the second driving mechanism and comprises:
an upper guide and a lower guide for forming a channel having an entry point on the front side of the buckle chute adjacent to the first driving mechanism;
a stop, disposed in the channel between the front side and the back side at a separation length from the entry point, for stopping a leading edge of said at least one sheet or the folded piece entering the channel from advancing further into the channel toward the back side so as to cause said at least one sheet or the folded piece to buckle at a locality thereof outside the entry point of the channel toward the second driving mechanism for forming a folded edge at the buckled locality by the second driving mechanism as the first driving mechanism continues driving said at least one sheet or the folded piece toward the buckle chute; and
an adjustment mechanism, mechanically engaged with the stop, for moving the stop toward the front side or the back side for adjusting the separation length.
According to the present invention, it is possible that the buckle chute further comprises a deflector mechanism, disposed near the entry point of the channel and operable in a first position, for allowing the leading edge of the said at least one sheet or the folded piece to enter into the channel when said at least one sheet or the folded piece is driven by the first driving mechanism toward the entry point of the buckle chute, or in a second position, for preventing the leading edge of said at least one sheet or the folded piece from entering the channel and further directing the leading edge toward the second driving mechanism.
According to the present invention, the adjustment mechanism comprises a screw system threadably engaged with the stop for moving the stop. The stop has a left end and a right end adjacent the left side and the right side of the turn chute, and the screw system comprises a first lead screw disposed near the left side for operatively engaging with the left end of the stop, and a second lead screw disposed near the right side for operatively engaging with the right end of the stop, and wherein the first and second lead screws are mechanically linked to each other such that the first and second lead screws can be caused to turn simultaneously for moving both ends of the stop by a substantially equal distance for adjusting the separation length.
According to the present invention, each end of the stop has an engagement mechanism for threadably engaging with the respective lead screw so that each end of the stop can be independently disengaged from the respective lead screw.
According to the present invention, the engagement mechanism comprises a split nut having grooves for engaging with the threads on the respective lead screw. In particular, the engagement mechanism comprises a first mount fixedly mounted to the first end of the stop; a second mount, movably mounted to the first end of the stop adjacent to the first mount, for fixedly mounting the split nut, wherein the second mount can be caused to move relative to the first mount to disengage the grooves of the split nut from the threads for disengaging one end of the stop from the respective lead screw.
According to the present invention, a spring is mounted between the first mount and the second mount for urging the split nut against the lead screw so as to firmly engage the grooves with the threads.
The present invention will become apparent upon reading the description taken in conjunction with FIGS. 1 to 8d.